I’ve reached the conclusion that there is likely no answer I can provide that will satisfy your curiosity.

Well, that's too bad. I would then suggest that you retract your "tuning services" post, because it does not seem that you have anything to offer anyone who doesn't wish to listen to music in a...VAAAYN DOWN BY THE RIVER!

(Especially when you claim on your website that your own system was voiced, which is to say "tuned," by someone else.)

Originally Posted by Whitledge Designs

In a former post, I asked you to explain why I’m swamped with home and car audio enthusiasts every time I exhibit - yet you failed to address the question.

No, I didn't. Please go back and re-read the exchange.

Originally Posted by Whitledge Designs

In addition, it appears that you prefer not to share information about your academic and industrial credentials along with pictures of your mobile audio system. You seem to be unwilling or incompetent to answer my question and share information about yourself and your mobile audio system. Why?

Because my points stand on their own. I don't need to appeal to authority. Besides, if you wished to learn that information, much of it is present on this site.

You claim the mantle of science, for instance, yet your only measurements on your website are single-point things taken off some handheld RTA, rather than more valid sound power measurements taken by spatially averaging several MLS responses? One of the key tenets of science is that one should be willing and able to defend one's chosen methodology. So, why the single-point measurement?

Three of these subwoofers combined provides for an equivalent single-transducer cone diameter of 15.86 inches, driven by about 3,300 W. By anyone’s measure, this is a large and powerful subwoofer system.

I would not say ANYONE.... Not all of us parade around the car audio circuits.

The Magic Bus currently uses three Dynaudio Esotar 1200 subwoofers, each powered by a Genesis Dual Mono Xtreme, which delivers about 1100 W of power. The effective cone diameter of the Esotar 1200 is 9.17 inches. Three of these subwoofers combined provides for an equivalent single-transducer cone diameter of 15.86 inches, driven by about 3,300 W. By anyone’s measure, this is a large and powerful subwoofer system.

Just a heads up, when people talk about very low frequencies around here they know what matters is not radiating area but volume displacement.

Your three woofers have a relatively small xmax (by modern standards, at least) of 10.25mm. (Dynaudio provides peak-peak figures, which are in fact 2*xmax.) So the total volume displacement of the three subs is 2.6L, ironically about the same as the displacement of your van's engine.

In a relatively small room, 2.6L of displacement down low should be plenty. Especially since the point of your system seems to be listening while stationary, given that your demos presumably happen in a parked car. What I find far less appealing is that you compensate for excessive dispersion in your mains speakers by excessive sound treatment, rather than taking the more efficient approach of restricting directivity at the loudspeakers and thus avoiding many of the reflections your treatments seek to control while allowing the development of lateral reflections for improved ASW.

[EDIT]Well, for starters according to JW he has abandoned the isobaric approach, using three drivers instead of six now.[/EDIT]

But you're wrong on fact. All going isobaric does is waste driver motors. One gains the ability to use a smaller box for a given Q, but also gives up half the efficiency.

Basically, isobaric loading is an antequated method of getting more more extended bass response in a smaller cabinet volume, nothing else. In the modern age we use DSP for that. It allows us to use fewer drivers, and not sacrifice efficiency over the whole bandwidth of the system.

Now, standard push-pull mounting has been shown to reduce even-order distortion. The degree to which that is audible is up for debate. (Not to mention that with many drivers any beneficial effects are swamped by the increased motor noise from an inverted driver. In fairness, the Dyn's are pretty crappy subs. They don't have much xmax, so motor noise is less likely to be a factor with them.)

See supra.

No. I would think it's a gigantic waste of time. Bass is the easiest thing in the world to get right, anyway. Everything else is much harder to get right in a car than sub-80Hz stuff.

Good points for sure ds and I agree with all of them. I especially always like to talk about the worth of something on the merits that they should be audible. On the push pull front, it's an easy measurable difference in distortion they is not in question. ..but if our unsophisticated hearing can take advantage of it, they might well not be able to as I believe hearing becomes less and less sensitive in the lower octaves, but one can't be faulted imo for doing something like this in an all out sq vehicle. I would definitely consider it myself and it might well merit valuable extra points during a competition if one competes and even if there is no appreciable difference in sound.

Good points for sure ds and I agree with all of them. I especially always like to talk about the worth of something on the merits that they should be audible. On the push pull front, it's an easy measurable difference in distortion they is not in question. ..but if our unsophisticated hearing can take advantage of it, they might well not be able to as I believe hearing becomes less and less sensitive in the lower octaves, but one can't be faulted imo for doing something like this in an all out sq vehicle. I would definitely consider it myself and it might well merit valuable extra points during a competition if one competes and even if there is no appreciable difference in sound.

Yeah. I don't think anyone was faulting him, though. The question that Jay brought up was how this information helps people with typical vehicles. That's what 99% of the members of this forum are interested in.

I haven't followed this whole "bus" saga closely, but it appears that Jon knows audio quite well. The question some folks may have (especially those who pay for his services) is how well he knows car audio. Obviously, there are a lot of folks that know a great deal about audio, but have never faced many of the obstacles unique to car audio. Jon fortunately got to mitigate a lot of those obstacles because of the vehicle he chose. So it's not obvious that his experience is useful in a different domain.

Again, I haven't followed his work closely. For all I know, he may have an entire repertoire of wonderful car installs under his belt. It's just hard to see it because of how much he keeps promoting this bus thing. At first glance, I thought he was offering services to other folks with buses/vans.

I consider the Magic Bus to be the ultimate demonstration vehicle – it combines every-day practicality and safety with high-performance audio in ways that surpass all other vehicles.

- Jon

This is why I never felt compelled to follow on the magic. When I listened to the bus at Marv's years back I thought you were one of the enthusiasts willing to teach and learn just like the rest of us. It's obvious now you are selling the buss. That is a bit of a disappointment to me as you don't seem to ever aknowledge that we know a few things too. How many cars do you listen to at a meet vs. bus demos? This may seem delusional so Ill procede with a few points on why some of the other cars in the world are not completely inferior to yours:

*the only sound the bus is going to make when needed to be parked in most cities around the world is a forehead hitting the horn. Which would you rather take on the streets of London, a Smart or the buss? Hint: a Smart can be parked perpendicular to the sidewalk.

*some guys have gone the extra length to sit in the middle of the vehicle. This applies to earlier comments regarding proper stereo reproduction.

*pathlength to the driver side speaker seemed short to me, Fits, Civics and the like have a shallower windshield slope which help a lot with placement.

*pathlength differences are exacerbated in the bus given how relatively far the right speaker is.

*Dynaudio is not the king of the hill in the least. For one custom underhung Skaaning drivers are Dyns on steroids. What about new technologies like BG with record low 3rd-11th harmonics?

*3300 watts dont mean anything when the drivers have low xmax, it's just a thermal rating.

*then there are the things that matter most in a car, efficiency, compactness, ease of removal,lightweight factor.

*heck, even time to completion, we are diy enthusiasts after all. Lifetime long completion solutions are not very apealing.

Bay Area. I just learned that Bing not only was planning a show in San Jose for Sept but that it will be regionals. Very exciting to have it held up here, and great venue (lots of space) to spread out in. Do you plan on making the drive up?